"Medicine is a social science, and politics is nothing else but medicine on a large scale"—Rudolf Virchow

July 16, 2014

A world without mosquitoes

As you might expect, I often wonder why we fret about great white sharks when mosquitoes kill hundreds of thousands of us every year. And I wonder why we don't mount a concerted effort to exterminate the species that kill and cripple us.

Serendipitously, while searching Nature News, I ran across this very interesting article from 2010: Ecology: A world without mosquitoes. After discussing the implications of extermination, especially for the Arctic, the article concludes:

Ultimately, there seem to be few things that mosquitoes do that other organisms can't do just as well — except perhaps for one. They are lethally efficient at sucking blood from one individual and mainlining it into another, providing an ideal route for the spread of pathogenic microbes.

"The ecological effect of eliminating harmful mosquitoes is that you have more people. That's the consequence," says Strickman. Many lives would be saved; many more would no longer be sapped by disease. Countries freed of their high malaria burden, for example in sub-Saharan Africa, might recover the 1.3% of growth in gross domestic product that the World Health Organization estimates they are cost by the disease each year, potentially accelerating their development.

There would be "less burden on the health system and hospitals, redirection of public-health expenditure for vector-borne diseases control to other priority health issues, less absenteeism from schools", says Jeffrey Hii, malaria scientist for the World Health Organization in Manila.

Phil Lounibos, an ecologist at the Florida Medical Entomology Laboratory in Vero Beach says that "eliminating mosquitoes would temporarily relieve human suffering". His work suggests that efforts to eradicate one vector species would be futile, as its niche would quickly be filled by another. His team collected female yellow-fever mosquitoes (Aedes aegypti) from scrap yards in Florida, and found that some had been inseminated by Asian tiger mosquitoes (Aedes albopictus), which carry multiple human diseases. The insemination sterilizes the female yellow-fever mosquitoes — showing how one insect can overtake another.

Given the huge humanitarian and economic consequences of mosquito-spread disease, few scientists would suggest that the costs of an increased human population would outweigh the benefits of a healthier one. And the 'collateral damage' felt elsewhere in ecosystems doesn't buy much sympathy either.

The romantic notion of every creature having a vital place in nature may not be enough to plead the mosquito's case. It is the limitations of mosquito-killing methods, not the limitations of intent, that make a world without mosquitoes unlikely.

And so, while humans inadvertently drive beneficial species, from tuna to corals, to the edge of extinction, their best efforts can't seriously threaten an insect with few redeeming features.

"They don't occupy an unassailable niche in the environment," says entomologist Joe Conlon, of the American Mosquito Control Association in Jacksonville, Florida. "If we eradicated them tomorrow, the ecosystems where they are active will hiccup and then get on with life. Something better or worse would take over."

I recall reading an account from the late 19th century about the surveyors determining the precise location of the US-Canada border on the 49th parallel, just south of the Fraser Valley. The mosquitoes were intense, inflicting misery of humans and horses alike; the surveyors spent much of their time huddled around smoky fires just to get a little relief.

Today the region where they suffered is a cheerful sprawl of well-drained Vancouver suburbs where mosquitoes are rare.

According to Worldometers, malaria alone has killed almost 2,000 people today, and over half a million this year. Those are deaths on a crimes-against-humanity scale. If we can't turn our talent for extinction against mosquitoes, we need to ask: Why not?

Comments

A world without mosquitoes

As you might expect, I often wonder why we fret about great white sharks when mosquitoes kill hundreds of thousands of us every year. And I wonder why we don't mount a concerted effort to exterminate the species that kill and cripple us.

Serendipitously, while searching Nature News, I ran across this very interesting article from 2010: Ecology: A world without mosquitoes. After discussing the implications of extermination, especially for the Arctic, the article concludes:

Ultimately, there seem to be few things that mosquitoes do that other organisms can't do just as well — except perhaps for one. They are lethally efficient at sucking blood from one individual and mainlining it into another, providing an ideal route for the spread of pathogenic microbes.

"The ecological effect of eliminating harmful mosquitoes is that you have more people. That's the consequence," says Strickman. Many lives would be saved; many more would no longer be sapped by disease. Countries freed of their high malaria burden, for example in sub-Saharan Africa, might recover the 1.3% of growth in gross domestic product that the World Health Organization estimates they are cost by the disease each year, potentially accelerating their development.

There would be "less burden on the health system and hospitals, redirection of public-health expenditure for vector-borne diseases control to other priority health issues, less absenteeism from schools", says Jeffrey Hii, malaria scientist for the World Health Organization in Manila.

Phil Lounibos, an ecologist at the Florida Medical Entomology Laboratory in Vero Beach says that "eliminating mosquitoes would temporarily relieve human suffering". His work suggests that efforts to eradicate one vector species would be futile, as its niche would quickly be filled by another. His team collected female yellow-fever mosquitoes (Aedes aegypti) from scrap yards in Florida, and found that some had been inseminated by Asian tiger mosquitoes (Aedes albopictus), which carry multiple human diseases. The insemination sterilizes the female yellow-fever mosquitoes — showing how one insect can overtake another.

Given the huge humanitarian and economic consequences of mosquito-spread disease, few scientists would suggest that the costs of an increased human population would outweigh the benefits of a healthier one. And the 'collateral damage' felt elsewhere in ecosystems doesn't buy much sympathy either.

The romantic notion of every creature having a vital place in nature may not be enough to plead the mosquito's case. It is the limitations of mosquito-killing methods, not the limitations of intent, that make a world without mosquitoes unlikely.

And so, while humans inadvertently drive beneficial species, from tuna to corals, to the edge of extinction, their best efforts can't seriously threaten an insect with few redeeming features.

"They don't occupy an unassailable niche in the environment," says entomologist Joe Conlon, of the American Mosquito Control Association in Jacksonville, Florida. "If we eradicated them tomorrow, the ecosystems where they are active will hiccup and then get on with life. Something better or worse would take over."

I recall reading an account from the late 19th century about the surveyors determining the precise location of the US-Canada border on the 49th parallel, just south of the Fraser Valley. The mosquitoes were intense, inflicting misery of humans and horses alike; the surveyors spent much of their time huddled around smoky fires just to get a little relief.

Today the region where they suffered is a cheerful sprawl of well-drained Vancouver suburbs where mosquitoes are rare.

According to Worldometers, malaria alone has killed almost 2,000 people today, and over half a million this year. Those are deaths on a crimes-against-humanity scale. If we can't turn our talent for extinction against mosquitoes, we need to ask: Why not?